I'll tip the Irish over Zimbabwe.
My problem with Ireland is their utterly awful showing in West Indies. On slow, sluggish, spinning tracks, their laid a total goose egg in the domestic 50/50 tournament that just took place there. I'm not sure they're ready to dominate on this kind of track.
TGambhir might be a fair candidate for a comeback though. He has shown fairly decent form in Ranji Trophy. Top scorer for Delhi with 1 century and 3 halfs. His case is strong mainly because of experience though, because quite a few other batsmen did much better than him overall.
Gambhir also has a tendency to perform in the clutch. He seems to have that mental makeup of a guy who craves the big matches and usually does well. I'm a bit of a Gambhir fan, and so I might be seeing something that others don't. I wish I could find some definitive stats, but remember it was Gambhir who top scored the last two times we won a world cup.